Bounded evidence contexts and a deterministic report outline.

POST /v1/charts/evidence returns a capped, relevant slice of a pair's geometry
for one topic, with the count it left behind. POST /v1/charts/report-outline
returns section identifiers in order with the evidence each rests on.

No prose and no model. The core supplies facts and identifiers; the words
belong to whatever renders them.

A section with no evidence is returned as unavailable with the reason rather
than dropped, because a silently missing section reads as a topic that did not
apply rather than one the geometry could not answer.

Additive.

618 tests, 1990 subtests, none skipped. ruff and mypy clean.